Selecting fermentation products for food waste valorisation with HRT and OLR as the key operational parameters
Copyright © 2021. Published by Elsevier Ltd.
| Publié dans: | Waste management (New York, N.Y.). - 1999. - 127(2021) vom: 15. Mai, Seite 80-89 |
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| Auteur principal: | |
| Autres auteurs: | , , , |
| Format: | Article en ligne |
| Langue: | English |
| Publié: |
2021
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| Accès à la collection: | Waste management (New York, N.Y.) |
| Sujets: | Journal Article Acidogenic fermentation Butyric acid Caproic acid Food waste valorisation Lactic acid Resource recovery |
| Résumé: | Copyright © 2021. Published by Elsevier Ltd. Acidogenic fermentation is attractive for food waste valorisation. A better understanding is required on how operation affects product selectivity. This study demonstrated that the hydraulic retention time (HRT) and organic loading rate (OLR) selected fermentation pathways in a single-stage, semi-continuous stirred tank reactor. Three combinations of HRT and OLR were tested to distinguish the effect of each parameter. Three fermentation profiles with distinct microbial communities were obtained. Predominantly n-butyric acid (13 ± 2 gCOD L-1, 55 ± 14% of carboxylates) was produced at an HRT of 8.5 days and OLR around 12 gCOD L-1d-1. Operating at an HRT two days longer, yet with similar OLR, stimulated chain elongation (up to 13.6 gCOD L-1 of n-caproic acid). This was reflected by a microbial community twice as diverse at longer HRT as indicated by first and second order Hill number (1D = 24 ± 4, 2D = 12 ± 3) and by a higher relative abundance of genera related to secondary fermentation, such as the VFA-elongating Caproiciproducens spp., and secondary lactic acid fermenter Secundilactobacillus spp.. Operating at a higher OLR (20 gCOD L-1d-1) but HRT of 8.5 days, resulted in typical lactic acid fermentation (34 ± 5 gCOD L-1) harbouring a less diverse community (1D = 8.0 ± 0.7, 2D = 5.7 ± 0.9) rich in acid-resistant homofermentative Lactobacillus spp. These findings demonstrate that a flexible product portfolio can be achieved by small adjustments in two key operating conditions. This improves the economic potential of acidogenic fermentation for food waste valorisation |
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| Description: | Date Completed 25.05.2021 Date Revised 25.05.2021 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1879-2456 |
| DOI: | 10.1016/j.wasman.2021.04.023 |